I think the main objection to rationals is that extensive computation with them tends to result in numbers requiring larger and larger amounts of storage. I believe that ABC made routine use of rationals, and this caused programs to get bogged down for no apparent reason, as rationals were being used behind the scenes when people didn't realise it.
So while rationals might be useful to have available for some things, you should have to explicitly ask for them. Returning rationals from '/' applied to integers would be a bad idea, for example. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
